Overview
The ZF 4108.302.198 SUN GEAR SHAFT is a critical internal component engineered for the WG100, WG130, and WG131 transmission series. This genuine OEM part serves as the central torque-transfer element within the planetary gear set, directly meshing with planetary pinions to modulate gear ratios and deliver smooth power flow. The shaft integrates the sun gear teeth into a single, hardened steel unit, ensuring precise alignment and minimal backlash during high-load operations. As a core rotating assembly member, it operates in close conjunction with the TRANSMISSION HOUSING and the HOUSING to maintain structural integrity under extreme torque. The SKU 4108.302.198 is laser-etched for traceability, guaranteeing it meets ZF’s original manufacturing tolerances.
Symptoms of Failure
- Audible gear whine or grinding during acceleration: Worn sun gear teeth produce a distinct high-pitched noise, often mistaken for bearing failure, as the shaft loses its hardened surface profile.
- Intermittent gear slipping under load: When the sun gear shaft develops pitting or spalling, the transmission may momentarily lose torque transfer, causing RPM flare without corresponding vehicle speed increase.
- Metallic debris in transmission fluid: Flakes or silver particles found during oil changes indicate advanced wear of the sun gear shaft’s tooth flanks, requiring immediate replacement to prevent cascading damage to the INTERM.GEARBOX assembly.
- Vibration through the shift lever or chassis: A worn shaft creates eccentric rotation, transmitting harmonic vibrations that worsen at specific RPM bands.
Technical Specifications
| Parameter | Value |
|---|---|
| Part Number | 4108.302.198 |
| Material | Case-hardened alloy steel (20MnCr5 equivalent) |
| Overall Length | 185 mm (estimated) |
| Shaft Diameter (bearing journal) | 35 mm (estimated) |
| Sun Gear Module | 4.5 mm (estimated) |
| Number of Teeth | 18 (estimated) |
| Weight | 1.8 kg (estimated) |
| OEM Reference | ZF 4108.302.198 |
| Surface Hardness | 58-62 HRC |
Compatibility
This sun gear shaft is specifically designed for ZF’s WG-series powershift transmissions. Verified direct-fit applications include the WG100, WG130, and WG131 models. It may also be compatible with certain variants of the WG180 and WG200 series, though cross-referencing the transmission serial number against the part’s spline count is recommended. The shaft interfaces directly with the COVER assembly and requires proper sealing via the SEALING RING to prevent fluid ingress. Always verify the TYPE PLATE on your transmission housing before ordering.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4108101128 | TRANSMISSION HOUSING | Encloses gear train; provides mounting points |
| 4108201296 | HOUSING | Supports planetary carrier assembly |
| 4475280018 | SCREW PLUG | Seals hydraulic passages |
| 0501215601 | OIL LEVEL GAGE | Monitors fluid level |
| 4108303034 | COVER | Protects sun gear shaft end |
| 0636015120 | HEXAGON SCREW | Secures cover to housing |
| 0636302015 | SCREW PLUG | Closes oil drain port |
| 0501325471 | SEALING RING | Prevents fluid leaks at shaft interface |
| 0730365280 | TYPE PLATE | Identifies transmission model |
| 4108108026 | INTERM.GEARBOX | Intermediate gearbox assembly |
ZF 4108.302.198 SUN GEAR SHAFT – Shaft RFQ Support
PartsZF supports RFQ preparation for ZF 4108.302.198 SUN GEAR SHAFT where shaft identification and documentation review are required before ordering.
Part-Number Summary
Use ZF number 4108.302.198 when sending your RFQ. PartsZF can review dotted, spaced, and compact number formats against the available product and documentation records.
Application Context
- Illustration section: INPUT
Cross Reference Support
If you have an OEM number, old supplier number, or visible marking, include it with your RFQ so PartsZF can compare it with the available records.
Specification Snapshot
| ZF part number | 4108.302.198 |
|---|---|
| Normalized SKU | 4108302198 |
| Part name | SUN GEAR SHAFT |
| Product category | shaft |
| RFQ support | Part-number lookup and documentation review |
| Media support | Product photo or diagram review when available |
Image and Documentation Notes
Current product media status: fallback. Product photos, diagram positions, and nameplate images help speed up part-number confirmation and quotation preparation.
RFQ Checklist
- ZF part number or OEM cross-reference number
- Machine model, transmission model, or nameplate photo
- Removed-part photos or visible markings
- Quantity, destination, and documentation requirements
- Final selection is confirmed by exact part number, machine context, and available documentation.
Related Parts
- ZF 2094.110.011 P.T.O. SHAFT
- ZF 2094.110.014 P.T.O. SHAFT
- ZF 4642.303.002 OUTPUT SHAFT
- ZF 2093.110.011 P.T.O. SHAFT
- ZF 5838.300.106 INPUT SHAFT
